1 would also anticipate finding not less than an innate (i.e. not caused right because of the drug but e.g. because of the anticipation to it) dopamine response to opioid administration in opioid addicts. Alas, although a single is found in animal models (and it's less than for psychostimulants), in https://riverntydc.oneworldwiki.com/7409341/the_ultimate_guide_to_ketamin_depression